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National Aquatic Resource Surveys: Multiple objectives and constraints lead to design complexity
Citation:
OLSEN, A. R. AND T. KINCAID. National Aquatic Resource Surveys: Multiple objectives and constraints lead to design complexity. Presented at The International Environmetrics Society's Third North American Regional Meeting, LaCrosse, WI, July 18 - 20, 2011.
Impact/Purpose:
The US Environmental Protection Agency began conducting the National Aquatic resource Surveys (NARS) in 2007 with a national survey of lakes (NLA 2007) followed by rivers and streams in 2008-9 (NRSA 2008), coastal waters in 2010 (NCCA 2010) and wetlands in 2011 (NWCA).
Description:
The US Environmental Protection Agency began conducting the National Aquatic resource Surveys (NARS) in 2007 with a national survey of lakes (NLA 2007) followed by rivers and streams in 2008-9 (NRSA 2008), coastal waters in 2010 (NCCA 2010) and wetlands in 2011 (NWCA). The surveys require national, regional and state-level estimates. These surveys are implemented jointly by USEPA, states, tribal nations and other federal agencies and as a result involve a variety of objectives and constraints. Typically, the survey designs are stratified by state and within a state unequal probability selection incorporates other design objectives. Sites are selected using a spatially balanced design. In addition to the core national surveys, supplemental studies that focus on specific subpopulations are integrated into the design. As an example, the NWCA 2011 survey design is a two-stage design. The first stage is based on an area frame design by the Fish & Wildlife Service’s National Status & Trends monitoring for wetland acreage change. The second stage design is a stratified, unequal probability survey design selected from wetland polygons identified from the first stage. In 2012, the second cycle of surveying each of the aquatic resources will begin with the NLA 2012 and includes objectives of estimating status in 2012 and change since 2007. This presentation will provide an overview of these surveys and discuss how the objectives and constraints for each survey were addressed.